Hyperglycemia is associated with poorer cognitive performance in a cohort of middle-aged people in Qatar: a cross-sectional study.

Background: Diabetes mellitus (DM) prevalence in Qatar is among the highest worldwide. DM has been shown to be associated with reduced performance on numerous domains of cognitive function in elderly population. Here, we sought to determine whether such association also exists in a middle-aged cohort.

Research design and methods: A cross-sectional study was conducted using data from 981 participants aged 40-65 years from the Qatar Biobank. We analyzed glycemic indices: HbA1c, serum glucose, insulin levels, waist circumference, and waist-hip ratio. Cognitive function was assessed using two domains of CANTAB: the paired episodic memory (visual memory) and reaction time (motor and mental speed).

Results: We found significant associations between DM and cognitive impairment. Poor reaction speed was linked to DM (beta 36.80, P < 0.01), higher HbA1c levels (beta 10.73, P < 0.05), larger waist circumference (beta 1.70, P < 0.001), and higher waist-to-hip ratio (beta 252.56, P ≤ 0.01). Poor memory performance was also associated with increased waist circumference and waist-to-hip ratio.

Conclusion: The negative association between DM, its biomarkers, and cognitive impairment reported previously in elderly populations also exists in middle-aged individuals. Further research is needed to explore the causality and impact of dysglycemia on other cognitive domains.